Note ♦
These utilities are compatible:
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with Enhanced Vision controllers only.
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with High-Speed Inputs (Reload)
HSC Frequency Measurement Utilities are three functions located on the More> Immediate menu. Together, you can use them to monitor a high-speed counter as a frequency value, and reset it if the changing frequency deviates from a set value.
The frequency can be measured from 0.25 Hz up to the maximum frequency that the PLC can read.
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Note ♦ |
These utilities are compatible:
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Frequency Measurement based on HSC
This element registers the frequency of the high-speed counter at each scan, and checks it against the frequency of the previous scan. If the change (delta) is greater than desired, the function sets an MB.
To use this function, place it in a net after an activating condition and select the desired high-speed counter. Once the function is activated, it continues to run until it is stopped by the application.
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Input |
Type |
Description |
Comments |
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A |
Constant |
High-speed counter |
This is the actual counter the function monitors |
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B |
MB, XB, SB |
Type of Deviation (0 = Percent, 1 = # of pulses) |
You can use either a percentage, or in .01Hz resolution by the 'C' input). Percentage: the range is 1 to 1000, where 1000 is 10 times the previous measured value # of Pulses: in 0.01Hz. ( 100 is equal to 1Hz) |
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C |
MI, XI |
Permissible Deviation from previous value (default 20) |
This is the legal 'Delta'; the difference between the current value and the previous value that was read. |
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D |
MI, XI |
Reserved, future use HSC Freq. Measurement |
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Output |
Type |
Description |
Comments |
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E |
MB, XB |
HSC Freq. Measurement: within permissible deviation |
Turns OFF when the between the current value and the previous value exceeds the permissible deviation. |
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F |
MI, Xi |
HSC Freq. Measurement: Status Messages |
• 0 - Valid data • 1 - No signal for time at least twice the permissible deviation (value in operand C). • 2 – Signal came after more than 2 sec (Less than 0.5Hz) • 4 – Higher frequency measured than the PLC can run • 8 - The change in frequency is bigger than the value in operand C • 10 - Reserve for system error |
|
G |
DW, XDW |
HSC Freq. Measurement: Result, in 0.01 Hz |
The frequency value |
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H |
DW, XDW |
HSC Freq. Measurement: actual HSC value |
This is the number of pulses from the counter |
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I |
MI, XI |
HSC Freq. Measurement: function’s Reload Value |
This is the actual high-speed counter's Reload value |
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J |
MI, XI |
Reserved, future use HSC Freq. Measurement |
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Stop Frequency Measurement
Use this function to stop the Frequency Measurement based on HSC function.
Reset HSC
Use this function to initialize the high-speed counter value.
